Notches on a internal splined cog

[igers562WV]

Working in a .ipt file, the attached shows a internal splined cog that has a notch on each tooth. I am trying to get the notches to change in count to match the count of teeth and still remain centered on the tooth.

I got the notches to constrain to the minor diameter so when I change the minor diameter to a larger or smaller number and back the notch follows suit.

The issue is when the count of the teeth change the notches do not remain constrained to the center of the tooth. I believe they are clocking from the original position which is based on the the angle of rotation origin.

The drawing is based on space width instead of tooth width therefore I had to start the notches using a formula of half the angle of rotation based on number of teeth, if that makes sense.

[mcgyvr]

Can you post the ipt file?

I'm not sure what variables you have between versions but why aren't you just sketching a single tooth with the notch included/constrained to the middle of the tooth profile and a circular feature pattern to array them around the internal. 

[igers562WV]

I did not draw the original sketch. It is from a template designed by a previous employee.

I was told when drawing up prints for internal teeth we use the space width measurement instead of the tooth width measurement. Which explains why the space width is at 12 o'clock and not the tooth.

I have included the .ipt file

[JDMather]

Sketch5 is not fully defined?

[igers562WV]

Forgive me, I am still a novice at this. Which part is not defined?

[JDMather]

What is the purpose of these two dimensions at the Origin in Sketch1?

[JDMather]

First thing I would do is sketch 3 circles at the Origin as shown...

[JDMather]

Then I would sketch a line of symmetry and the two angled lines as shown.

[JDMather]

Note the simplicity of the sketch thus far...

[JDMather]

Examine the Attached.

You will have to determine if you want to add a relation between the Number_of_Spaces and the ID.

[igers562WV]

I cannot answer that question, I did not draw the original sketch. It appears to be "half_space_width_origin"

[igers562WV]

This seems to be working. However, I need to be able to suppress the notches and notch fillets. Not all cogs will have notched teeth.

[JDMather · Accepted solution]

The do that feature as a separate feature and feature pattern.

You can then alter the pattern or suppress individual occurrences.

[igers562WV]

JD, I finally figured out how and where to use the formula you supplied: 180 deg / number_of_spaces.

I also had a template for a internal involute spline that was a little trickier to resolve, but I did manage.

Thanks so much for your help.

I will mark your solution as accepted.